There have conventionally been some techniques developed for checking the operations of a computer program. There have also been other techniques developed for comparing how differently a computer program behaves, when the computer program is corrected due to a program upgrade or the like, with the computer program before the correction.
To find out which part of the computer program has been modified based on a plurality of computer program behaves, because users have traditionally inferred from the differences in pieces of behavior information acquired from the respective computer programs, such an analysis has been rendered difficult. Conducting sufficient analyses of the operations of a plurality of computer programs have been thus difficult.